Spin squeezing is an important concept in quantum mechanics, which was found closely related with the criteria of entanglement in quantum information. A theoretical scheme for generating spin squeezing state in spinor Bose-Einstein condensate (SBEC) with a laser pulse was put forward. Using the single-mode approximation, the time-dependent wave function of SBEC were obtained, and the analytical expressions of the squeezed angle and spin squeezing parameter were obtained. By investigating spin squeezing in SBEC, it’s found that the spin squeezed state with more squeezing can be generated by increasing coupling strength between laser pulse and the condensate.